Process of and apparatus for detecting solder pellets in cans



4 She ets-Sheet 2 March 2 1933- R. o. HENSZEY ET AL PROCESS OF AND APPARATUS FOR DETECTING SOLDER PELLETS IN CANS Filed June 19, 1936 e 1 u w M 8 Y M M a w w T, W a w Q z A R r z w 4 5 H A. J w 9 WW 6 iqmfly ll lh 3 -i lliillll E L W o Tm P a u Q a m l C 0 w R DISCA I2 DIIVG STA T'ION TEST/N6 6 TA TION March 29, 1938.

o. HENSZEY r AL PROCESS OF AND APPARATUS FOR DETECTING SOLDER PELLETS IN CANS Filed June 19, 1955 4 Sheets-Sheet 3 SOLE N010 W m 2 Y. v s s w a v m m w m. m E O m 0 E eld U W 5 a L ww w 2 v m 2 v m l w B WW m m w m 2 4 w V ,2 s WM H A n Jul/z mm a H 7 V 1 NA f & EP .11 mWWN h \N C O m6 i rt 4 W l R Q MN. 7 m MN N v 5% \mnmu NW N k u @.N 4 N. M rm. w- M k N NN 3v NR $H March 29, 1938. R. o. HENSZEY ET AL PROCESS OF AND APPARATUS FOR DETECTING SOLDER PEDLETS IN CANS 4 Sheets-Sheet 4 Fiiedw June .19, 1935 4/ ROY 0. HENSZE PAUL 1504/2121;

Patented Mar. 29, 1938 UNITED STATES PROCESS OF AND APPARATUS FOR lIlE'lEGT- ING SOLDEB. PELLETS IN CANS 7 Boy 0. Henszey, Hans Buehler, and'l'aul Smart,

Oconomowoc, Wis.,

assignors to Carnation Company, Oconomowoc, Win, a corporation of Delaware Application June 19, 1936, Serial No. 86,212

15 Claims.

Our invention relates to process of and apparatus for detecting solder pellets in cans. The process of our invention comprises bringing a can into close proximity to a vibration sensitive detector, moving the can in such manner that any pellet contained therein is caused to strike the can wall thereby producing a. vibration of said can wall capable of being detected, said vibration sensitive detector with its associated apparatus 10 being responsive to the vibration produced by said pellet but being relatively insensitive to extraneous vibrations, then-transmitting the response of said detector, usually after amplification, .120 means for indicating the presence of any pellet in said can and, if desired, transmitting said response to means for automatically rejecting any pellt-containing cans. The apparatus of our invention comprises a vibration sensitive receiver or detector, means for conveying a pluralityv of cans some of which contain solder pellets seriatim in close proximity to said vibration sensitive de-- tector, means for setting said cans into forced vibration while in close proximity to said detector, said forced vibration being capable 'of causing 5 any pellets to vibrate against the walls of said cans thereby producing a vibration diflerent from said forced vibration, said detector and associated 40 sealed by placing a drop of solder in the vent- It is dif-- holeand allowing it to harden there.

ficult to prevent the solder from dropping through the vent-hole into thecan and this method invariably results in the inclusion of sol- 5 der pellets in at least a small proportion of the cans. The presence 01' these pellets in cans containingfoodstufls is highly objectionable.

The present invention comprises an automatic method for'detecting and discarding cans con-- taining such pellets. I

It has formerly been the practice to detect pellets in cans by shaking the sealed cans close to the ear and listening for the slight click or noise produced by the pellet striking the wall of 55 the can. This hand process is, of course, ex-

pensive'and highly unreliable. Invariably a certain proportion of cans are passed by the inspectors, which contain pellets. Owing to the high viscosity of many food products, such as evaporated milk, and the resulting sluggish move The present invention makes it'possible. to de- 4 tect pellets which are the size of pin points and which make so little noise when the can is shaken that any noise produced thereby is inaudible to pletely automatic or may be operated to produce a visual indication of the presence of pellets with manual removal of the cans containing such pellets. The method can be operated with great speed and precision. s Broadly speaking our method comprises vibrating a can in such fashion that any pellet con-- tained therein is caused to strike a wall of the' can thereby producing avibration or'noise which is capable of being detected automatically. This vibration or noise is detected by a receiving means which is advantageously tunedin such manner that it is sensitive to the vibration produced bythe pellets striking'the can wall but is relatively insensitive to extraneous noises, such as the splashing of the milk and the vibration whichis applied to the can. The impulsewhich isireceived is then amplified, usually electrically,

and this amplified impulse is employed to produce avisual indication of the presence of any pellets or to set in motion mechanical elements which v are capable of automatically discardingany cans which contain pellets. The vibration applied to the can is usually a simple shaking produced by a quick dropping of the can'and the receiver may be any noise or vibration sensitive device such as a telephone receiver, microphone or the like. We have found it particularly advantageous to vibrate the can while in a magnetic field and in such a position that a magnetic flux passes through the can wall, the variations in flux produced by the pellet vibration'being then detected by the corresponding variations in an electric current induced'thereby.

Our invention can be explained more specifically by reference to the accompanying drawings which show an assembly of apparatus elements within the purview of our invention and susceptible of use in our process. In this showing:

Fig. l is a vertical section through a machine rier arms which support the cans before and after v astestin Fig. 7 is a perspective view of the mechanism attached to a solenoid whichysvhen operated,

serves to automatically discard cans containing pellets,

Fig. 8 is a view of a switch which re-sets the solenoid mechanismaiter the discarding of a can, Fig. 9 is an enlarged sectional view of the vibration detector, with parts in elevation,

Fig. 10 is a diagram of electrical connections which can be employed for detecting and amplifying the impulse received by the detector and for operating the solenoid as a result of said impulse, while- Fig. 11 shows-a modified method of vibrating the cansasthey are being tested. I

In the various figures, like parts are represented by like reference numerals. Our machine is mounted on a pedestal base I which supports a fixed vertical shaft 2. A gear housing I is supported by the vertical shaft and this provides a mounting for a motor, not shown, and driving worm 4, mounted on the motor shaft 5. The worm gear I meshes with a gear which is secured to a sleeve 1 journaled on shaft 2. A turret I is boltedto sleeve 1 and journaled on shaft 2, this turret serving to support and rotate a series of carrier arms (see 6), which are pivoted at II to brackets bolted to said turret. The, carrier arms bear upon the fixed annular cam II which is supported by brackets l3 mounted on gear housing3;seeFigs.1,4and5.

The top of the vertical shaft {is reduced in diameter andafixedeap ilissecuredtothisby means of set screw II. This cap is provided with flat sides to which are secured bracket it, which supportsthe solenoid i1, and two cams II and I. (see Figs. 1 and 2) which serve to operate the claw grip ll which holds and carries the cans II. The cap i4 is provided with a counter bore 22 at its lower end which provides room for the ball bearingracefl whichissecuredtotheturretl by means of the clamp ring 24. As shownin Fig. 5, the cam llis provided with two vertical sections II and It forming one side v of pockets 2! and 3.. As the carrier arms 0 pass along the cam from right to left in Fig. 5 a sharp drop is produced atthese two points. The arms strike the springs 21 and 28, the ends of which are. positioned in pockets 2! and ti, respectively, (see Figs. 3 and 5) and the cans which are held by these arms thus receive a-sudden Jolt or vibration at these two points. The first drop serves to accm-atelyposition any pellets It in the cans while the second drop causes the pellet to strike ,the

can wall thereby producing a vibration or noise which is detected in a manner to be described.

"The springs 21 and fl'aremounted on brackets 81' and 84, respectively whichinturn are secured tothe gear housing 3.

-Rei'erringtoFig.2,thecanstobetestedare fed to the machine by means of conveyor 33 and removed by conveyor M. The cans are automatlcally gripped at conveyor 83 by the claw grips II and are automatically released at conveyor 34. The claw grips are formed in two parts (see Fig. 6) one maybe termed the hand part It being integral with the carrier arm 9 while the other fin- I ger part It is pivoted at 31 tothe carrier arm. The pivoted part," is provided with a finger It having at its end a tapered raised cam portion 39 with a beveled edge. The fingers it serve as cam followers, cooperating with cams i8 and H to operate the claw grips, as shown in Fig. 2. The carrier arms 9 are provided with bosses 40 which act as a stop for fingers 3|. Theseflngers are normally held in closed or gripping position by meansof springs II which tend to press the fingers 38 against the'bosses 40, as will be clear from Fig. 6. The springs, II are supported by and act between raised portions 42 on hand part 3! and raised portions 39 on fingers 38. The inner faces oi the claw grips are provided with rubber linings 43 which provide a positive gripping action and reduce the severity of extraneous vibration carried to the can through the claw grip.

It is generally advantageous to provide means whereby the carrier arms are forced to drop of! the cam portions 25 and 20 with a velocity higher than that produced by gravity alone. The pellets. tend to fall at the rate which would be produced by gravity and thus become spaced from the can wall. When the downward motion of the can is thensuddenly arrested by the springs 21 and It,

any pellet is caused to strike the can wall sharply. This forced dropping of the cans may be produced by the springs M and 45; see Fig. 2. These springs are mounted on cap ll by means of arms 46 and 41, respectively. Spring 44 normally bears on the top of the cans, as shown in Fig. 3 while spring 45 bears on the carrier arms ,9, as shown in'Fls. 1.

The detector, indicated generally at 48 in Figs.

1 and 9, is adJustably mounted on arm 49, which is secured to housing 3 at the testing station immediately below the second drop produced by camv section 28. The detector is adjusted in height so that the cans, at the lowest point of their second drop, are immediately above the detector, as shown in Fig. 9.

We have found it advantageous to employ a detector very similartothe ordinary telephone receiver. We have found, however, that. greater sensitivity and selectivity: are secured provided the soft iron disc found in the usual telephone receiver is removed. The can bottom 50 then takes the place of this soft iron discand variations in the distance of the can bottom from the permanent magnetJl (Fig. 9) produce corresponding variations in magnetic flux which in turn induce currents in the'magnetcoils'fl. The path ofthe flux through the can bottom is indicated by dotted linesandarrows inl'igs.9and 10.

The detector shown in Fig. 9 is insensitive to noises at all times when the can bottom isremovedfrom its immediate vicinity. Moreover the can bottom itself is-relatively-insensitive to ex- But traneous noises originating outside the can. them of a pellet on. the, can bottom di- 1 vibrates the same and this vibration is di- I transformed into the desired electrical impulse. This avoids the loss of energy-which would result' from the indirectmethod of producingilo sound waves in the air, followed by reception of metal'ca'se I, are mounted in these sound waves and to eleca rubber packing 53, this packing being secured between the two metal halves 54 and 55, shown in Fig. 9. Electrical connection to coils 52 are made gram of which is shown in Fig. 10. The discarding means comprises the solenoid I! (Fig. 1) with connecting rod 59, pivoted to its plunger. The solenoid bracket I6 is provided with horizontal arms 60 (see Fig. 7) in the ends of which is pivoted a bifurcated rocker arm 6| which is pivoted at one end 82 to connecting rod 59. A cam roller 63 is secured to the other end of rocker arm 6| in the manner shown in Fig. 7. It will be evident from this showing that, when connecting rod 59 is raised by actuation of the solenoid, the cam roller 63 will be lowered. In its normal position, shown in Fig. 1, the cam roller 63 is raised above part 39 of the fingers 38 of claw grip 20. But

when the solenoid is actuated the disc drops into the path of the claw fingers and operates to open the claw grips as the carrier arms move past; see Fig. 2.

The electric switch, indicated generally at 54 (see Figs. 2, 8 and 10) is mounted on a block of insulation on the end of rockerarm 6!. This spring, as will be evident from Fig. 8, is normally held in closed position by the spring action of the upper leaf 66 but is opened, after excitation of the solenoid, by the cam portions 39 on fingers 38 of claw grips 20, after the cams have left the testing station. This switch 64 has the purpose of restoring the solenoid to its normal or inoperative position after the discarding of a can containing a pellet, as will be described later.

The wiring diagram of a suitable receiver and controller for operating our device is shown in Fig. 10. At'the left in this figure is shown the detector 48 with wiring connections to the coils 52, one end being grounded at 51. The wiring connections are believed to be clear from the legends in Fig. 10.

Many suitable wiring diagrams for our receiver can be developed. It is only necessary that the receiver amplify the impulse received from the detector and employ this amplified impulse to operate the hold-in relay' 68. A sensitive relay 69 is usually employed, this being operated by the current from a gas filled tube II! which acts as an I electronic trip. This trip 10 is generally connected in the circuit after one or more stages of amplification, as shown in Fig. 10. We have found that an electronic trip is superior to an electro-mechanical trip, because the voltage of tripping may be adjusted and is then constant, and because the trip is caused by instantaneous peak voltage rather than by some function of voltage and time; This is particularly important in the present invention since the pellet sound is extremely short in duration owing to the damping action of the milk. Interfering noises are usually more sustained in length.

When the electronic trip Ill is operated it energizes the sensitive relay 59 which in turn operates hold-in relay 88. This r'elay.energizes the solenoid H (see also Fig. 1) and the solenoid re-' mains energized imtil electric circuit of relay 68 is broken by opening of switch 84. As described previously, energization of solenoid l'l causes the cam roller 63 to drop in position to operate fingers .automatic.

e 88 on claw grips 28. This causes the claw grips Q to release the cans and the cans drop by gravity and are thereafter discarded. It is, of course, evident from the preceding description that the solenoid I1 is caused to operate only when the can at the testing station contains a pellet. The switch 64 which is mounted on rocker arm 5|- drops downin the path of cam portions 39 of fingers 38 only when a pellet has been detected.

And as soon as the switch 64 has been opened the solenoid is restored to ,its inoperative position and the rocker arm 6| lifts the switch 64 out of the cathode resistor when it is tripped. Thus the re* jecting apparatus shown in the drawing is fully We may use other methods also.

The description of the operation of our pellet testing and can discarding device may be summarized as follows: A series of cans are fed into the machine by means of conveyor 33. At this point, during the rotationof the turret or turn table 8, the claw grips 20 are opened by operation of cam l9. These claw grips grasp the individual cans and carry them clockwise around the turntable, as indicated by the arrow in Fig. 2. Along the section line 33 of Fig. 2 the pivoted carrier arms 9, which are supported by cam 12 (see Fig. 5) drop into pocket 29 and the cans are given a sudden jolt and are tilted slightly. This jolt serves to loosen any pellet l6 and to tumble it into the lowest point of the can, thereby definitely localizing its position. The carrier arms are .then raised by the beveled portion 3! of cam I2. As the cans reach the testing station directly above the detector 48 (see Fig. 2), the carrier arms drop into pocket 30 of cam l2 (see Fig. 5) and strike nent magnet 5| and a corresponding electrical,

impulse in coils 52. This electrical impulse is amplified by the vacuum tubes shown in Fig. 10 sufliciently to actuate therelay 69. Relay 69 in turn actuates the hold-in relay 68, which upon closure, energizes the solenoid l1. Operation of the solenoid raises the connecting link 59 causing the cam disc 63 to drop into a position to contact part 39, the cam portion of finger 38 on claw grip 20. And, as the rotation of the turret carries the pellet-containing can past the cam disc 63, the claw is opened and the can drops by gravity or it may be pushed from the claw. The can is thus automatically discarded at the discarding station. Soon after this operation the switch 64 (Fig. 8) is opened. This breaks the circuit of the hold-in relay 68 which opens thereby breaking the electrical circuit to the solenoid II. The connecting link- 59 drops and the cam roller 63 and switch 64 are raised to their normal or inoperative position justbefore the next succeeding can reaches the testing station.

If the tested can does not contain a pellet the sudden drop of the can at the testing stationproduces only those electrical impulses in the detector coils towards which the receiver and associated apparatus is relatively insensitive. The 15 relay ll is'not operated and the solenoid l'l, cam disc I! and switch it remain in their inoperative positions. The pellet-free can is therefore carried past the discarding'station and is finally 5 released from the claw grip 20 by operation of cam II. The can then leaves the machine means of the conveyor 34. a

By means of the machine described and illustrated we have found it possible to test-cans at the rate of up to 135 per minute. Pellets as small as pin points have been detected. Both of these results were impossible prior to the present invention. While we have described what we consider to is be an excellent and practical embodiment of our invention it is immediately obvious that many modifications can be made within the skill of the art which fall within the purview of our inven-' tion. Our method depends upon the application of a forced vibration to the cans to be tested, this vibration being of a type causing thepellet to bounce and to strike the can wall, thus producing a vibration in said wall which is capable of being detected and diiferentiated from the forced v1 brationh The pellet-produced vibration or the resultant vibration of the can wall may differ from the forced-vibration by a diflerence in pitch.

a diflerencein quality or a difference in amDlitude;. the only requisite being that this differ- 80 ence is capable of being detected.

With the apparatus shown in; our drawings in which the pellet impact is caused by sudden arresting of the downward motion of the can, the frequency of the vibration caused by the pellet to impact is a rather highaudio frequency. The

extraneous vibration caused bysuchthings -asthe splashing of the contents of the can, the operation of the machine,.floor vibrations,. and

sound waves, are sufiiciently lower in frequency so to be adequately eliminated from. the amplifier output'by selective'amplification.

In Fig. 11 there is shown anoptional method of causing vibration of the cans for testing purposes. In this showing thecan II is given a chattering motion by means of two electromagnets '9 and II energized by two separate coils II and II, respectively.

coils ll and 12 may be such that the current in one circuit lags behind that in the other by so about half a cycle. In this case the electromagnetswiil be energized alternately and a chattering motion of can II will be produced. It is desirable to have the cans rest upon rubber strips ii and I4 and a rubber pad II mayjbe employed as at the top to prevent actual contact of thef'can with the iron magnets. The detector ll employed in this embodiment may be of the same type as that shownin the other figures.

' The method of detecting the diiference vl- I do bration of the can bottom caused by the presence of a pellet may, of course, vary widely, It is pomble to detect this diiference mechanically or electrically or by a combination of these methods. When the diiference isdetected electrically it is immediately evident that a wide selection of detecting and amplifying methods are available.

That illustrated in the drawings is only one of It is possible, 0! to mine "1.; ss'in Fig. l0byanyoftheusualindicatingdevices.' m.

thiscaseourmethodmaybemanualinsofar asthediscardingof the'pellet-containingcansis concerned'while being electrical and mechanical "in so far as detection pellets is concerned.

The electric circuits of It isalso possible to mark the cans containing pellets in various ways.

As has been indicated previously, a conventional microphone may be employed as a detector in our; invention and the pulsating micro- 5 current'resulting from the noise produced by the pellet can beamplifledbymeans familiarinthe radio art. The amplified current can be employed in such manner that 'in eflect the noise of the bounding pellet is merely amplified. It l0 is also possible to employ the principle of the called condenser ,microphone in making a detector. r

\ The amplifier shown is sensitive to high audio frequencies while being relatively insensitive to islow frequencies, this, being accomplished by choice at constants in the'coupling circuits of, the amplifier. The sameresult canbe accom-' plished, of course,by' other well-known methods. L Resonant circuits may be used with or so a beat frequency oscillator. 1

. The tube II in Fig. 10 ,is so connected that it carries a heavy current .for a short time after any peak signal voltage higher .than a naked value is applied to its grid. Relay 8! is operated by 26 this tube. Tube 10 and relay 69 may also represent deviceswhich are designed to operate at a certain value of a function of voltage and p tion of voltage.

In a modification of this invention relay II may 80 represent a time lag relaywhichioperates to en-. ergize the solenoid I] for 'a deflnite shorttime in-, terviii, this interval corre nding to the time required for a can to traverse the distance from the testing station to the station. as

The presentinvention is applicable to problems other than that of detecting solder pellets in tin cans. It is generally applicable for the detection of solid bodies in containers holding fluids provided the said solid bodies are' of diflerent 4o.'

specific gravity than the said fluids and the material of the container is such that a vibration capable of being detected is produced upon the striking'of the container walls with saidsolid bodies. Cardboard and wooden containers are, examples 'of containers which within the present invention.

Other commercial applications and methods of operating the process of the present inveni tion, which fall within the scope of the following so 1' claims, will immediately occur to those skilled in the art, i

What we claim is:

1. An apparatus for detecting the presence of .solid bodies in containers holding fluids, comprising a vibration sensitive detector, means for continuously moving a container past and into close proximity to said detector, means mimoving said container-"bodily while in such position in.

v such manner as to cause any solidbody contained w i therein to strike a wall of said container thereby producing a vibration of said wall, and means for converting the resulting response of said detector into mechanical action to indicate thepresence ofanysuchsolidjbody. 1 '2. An apparatus for detecting the presence of solid bodies'in containers holding fluids, compris- 3 ing a vibration sensitive detector, means for continuously'moving'a container-past and into close. proximity to said detector, means for: applying 70 a forced vibration to said container while in such proximity of such type that 41! 3 .6 body there- ,inis caused to strike it'wall of said container thereby producing a resultant vibration diiier- I eat from said forcedvvibration, said detector be ing sensitive to said different vibration but relatively insensitive to said forced vibration, and means for transforming any response to said detector into mechanical action capable of indicating the presence of any solid body insaid container.

3. An apparatus for detecting solder pellets in cans containing fluids, which comprises avibration sensitive detector, means for continuously passing a plurality of cans seriatim in a path leading in close proximity to a said vibration sensitive detector, means for applying a forced vibration to said cans while within the field of and while moving past said detector, said vibration being 'of a type causing any pellets contained in said cans to strike the walls of said cans thereby producing a vibration difiering from said forced vibration, means for selectively amplifying the response to said detector to said different vibration and means for converting said amplified response into mechanical action capable of designating any cans containing pellets.

4. An apparatus for detecting solder pellets in cans, which comprises a vibration sensitive detector, means for moving a series of cans along a predetermined path intersecting the field of said detector, means for applying a forced vibration to said cans while in the field of said detector, said vibration being of suflicient intensity to cause any pellets in said cans to strike the can walls, means for amplifying any high audio frequency response of said detector and means for employing said amplified response for actuating means for removing any pellet-containing cans from said predetermined path.

5. An apparatus for detecting solder pellets in metal cans, which comprises means for moving a plurality of cans seriatim along a path, means for applying a forced vibration to said cans at a predetermined point in said path, said vibration being of suiiicient intensity to cause any pellets contained in said cans to strike the walls of said cans thereby producing a vibration difierent from said forced vibration, means for passing a magnetic flux throughthe walls of said cans when at said predetermined point, means for transforming variations in said magnetic flux produced by said difierent vibration into an electric current, means for amplifying said electric current and means actuated by said electric current for removing any pellet-containing cans from said path.

6. An apparatus for detecting solder pellets in cans which comprises a vibration sensitive detector, means for passing a plurality of cans along a predetermined path seriatim, said path entering the field of said detector, means for causing said cans to drop abruptly and for suddenly arresting said'drop while said cans are within said field, thereby causing any pellets in said cans to strike the can walls, means for am plifying any response of said detector to the vi bration resulting from the striking of said can walls and for converting said amplified response into mechanical action capable of designating any cans which contain pellets.

7. An apparatus for detecting solder pellets in cans, which comprises a plurality of grippers,

said point, means for producing a vibration ofthe gripped cans in such fashion as to cause any pellets contained therein to strike the can walls,

means for picking up the resulting vibration of said can walls and for designating which cans contain pellets, and means for releasing the cans from the grippers before the grippers reach said point at which they are operated to receive cans.

8. In the process of detecting solid bodies in containers, the steps which comprise passing a container along a predetermined path, passing in proximity to a vibration sensitive detector, tipping and shaking said'container at one point in' said path in order to definitely position any solid bodies in said container, then vibrating said container while in motion along said path in such manner-that any so positioned solid bodies are caused to strike the wall of said container while in immediate proximity to said detector, said detector being responsive to said vibration, and

converting any response of said detector into imity to said detector and for moving said container in such manner that any solid body contained therein is caused to strike a wall of said container while within proximity to Said detector, thereby producing a vibration of said container wall, means for selectively amplifying any high audio frequency component of said vibrationpicked up by said detector and means ac'- tuated in response to said amplified vibration for indicating the presence of any solid body in said container.

10. An apparatus for detecting the presence of solid bodies in metal containers, comprising electrical means for producing a magnetic flux,

means for positioning such a container in such proximity to said electrical means that said magnetic flux will pass through .a wall of said container, means for vibrating the so-positioned container in such fashion that any solid body contained therein is caused to strike said wall thereby producing a vibration of said wall, and means responsive to the resulting variations in said magnetic flux for indicating the presence of any solid bodies in said container.

11. An apparatus for detecting the presence of solid bodies in containers, comprising means for continuously moving a container at a substantially constant velocity along a predetermined path, means for vibrating said container at a predetermined point in said path without substantially disturbing said continuous motion along said path, said vibration being in a direction substantially at right angles to the direction of-said continuous motion and being capable presence of any solid body in said container.

12. An apparatus for detecting the presence of solid bodies in containers, comprising a vibration-sensitive detector, means for passing a plurality of containers seriatim along a predetermined pathpassing in close proximity to said detector, means for suddenly vibrating said containers while 'in motion along said path and while in proximity to said detector, said vibration being capable oi. causing any solid bodies'in said containers to-strike the walls 6': saidcon-s of said walls, meansfor amplifying any of said detector to said resultant vibration an means actuated by said amplified response for indicating the presence of any solid bodiesin any .of said containers.-

13.- The'apparatus of claim'12 wherein said means for suddenlyvibrating said containers comprises means for dropping and quickly a.r-

resting said containers.

14'. The apparatus of claim 12 wherein saidpredetermined path is the arc of a circle lying in a substantially horizontal plane.

15. An apparatus for detecting the presence of solid bodies in container, comprising a vibrationsensitive detector and a plurality of grippers,

means for passing saidgrippers through a closed path passing in proximity to said detector, means 1 vfor presenting a plurality of containers to said grippers scriatim at one point in; saidpath,-

means for operating said grippers to receive said containers at said point. means for vibrating vibrations, means for amplifying any responses of 10 said detector to said resultant vibrations, means actuated-by said amplified responses for releasing any containers holding solid bodies at a third point in said closed path and means for releasing containers free from solid bodies at a fourth 1s point'in said closedpath.

- ROY 0. HENSZEY.

HANS BUEHLER.

PAUL SMART. 

